This proposal will study the neurochemistry of tetrahydroisoquinoline alkaloids (THQ) in rats treated with various doses of ethanol. This research is designed to (1) demonstrate in vivo formation of THQ after patterns of ethanol administration in animals which simulate those ingestion in humans. Identification and quantitation will be facilitated by use of a refine gas chromatographmass spectroscopy method. (2) Study regional and subcellular distribution of THQ, and their effects on slected neurotransmitters and enzymes involved in the methabolism of these neutrotransmitters. (3) Study the kinetics of THQ inhibition on those enzyme systems shown to be inhibited in (2).